Latency reduction techniques for radio access networks

ABSTRACT

Latency reduction techniques for radio access networks are described. In various embodiments, a reduced transmission time interval (rTTI) may be implemented in order to reduce air interface latency in a radio access network. In some embodiments, an rTTI block may be defined, and some operations may be performed in rTTI block-wise fashion in order to reduce the marginal overhead associated with implementation of the rTTI. In various embodiments in which an rTTI is implemented, DM-RS granularity may be improved by use of techniques that enable data and reference signals to be multiplexed within a same OFDM symbol. In some embodiments, a current transmission time interval (TTI) may be maintained, and latency reduction may be achieved via the use of novel techniques for one or more of code block (CB) segmentation, uplink (UL) resource element (RE) mapping and HARQ cycle timing. Other embodiments are described and claimed.

RELATED CASE

This application claims priority to U.S. Provisional Patent ApplicationNo. 62/169,276, filed Jun. 1, 2015, United States Provisional PatentApplication No. 62/169,946, filed Jun. 2, 2015, and U.S. ProvisionalPatent Application No. 62/169,956, filed Jun. 2, 2015, each of which arehereby incorporated by reference in their entirety.

TECHNICAL FIELD

Embodiments herein generally relate to communications between devices inbroadband wireless communications networks.

BACKGROUND

Latency reduction for Long-Term Evolution (LTE) has been identified asan important consideration with respect to the future path of LTE. Asnoted in a recent study item proposal, reducing latency can increasethroughput by improving the performance of transmission control protocol(TCP) in the upper layers, by reducing the impact of TCP slow start, amajor limiting factor for small size packets. Furthermore, reducing theair interface latency of LTE can enable a new, emerging category ofservices known as ultra-low latency and mission critical traffic. Suchnew services were identified as important for use cases such asvehicular networks, among others, in a 5G White Paper published by theinfluential Next Generation Mobile Networks (NGMN) alliance of mobileoperators. Ultra-low latency services are expected to require one-wayair interface latency to be on the order of 1 millisecond or less, whichis represents a significant reduction with respect to current LTElatency.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates an embodiment of a transmission timing diagram.

FIG. 1B illustrates an embodiment of an operating environment.

FIG. 2 illustrates an embodiment of a first reference signal design.

FIG. 3 illustrates embodiments of second and third reference signaldesigns.

FIG. 4 illustrates an embodiment of a mapping process.

FIG. 5 illustrates an embodiment of a multiplexing pattern table.

FIG. 6 illustrates embodiments of a fourth reference signal design.

FIG. 7 illustrates embodiments of a fifth reference signal design.

FIG. 8 illustrates embodiments of sixth and seventh reference signaldesigns.

FIG. 9 illustrates embodiments of eighth and ninth reference signaldesigns.

FIG. 10 illustrates an embodiment of a first mapping scheme.

FIG. 11 illustrates an embodiment of a second mapping scheme.

FIG. 12 illustrates an embodiment of a third mapping scheme.

FIG. 13 illustrates an embodiment of a first HARQ cycle and anembodiment of a second HARQ cycle.

FIG. 14 illustrates an embodiment of a third HARQ cycle and anembodiment of a fourth HARQ cycle.

FIG. 15 illustrates an embodiment of a fifth HARQ cycle.

FIG. 16 illustrates an embodiment of a sixth HARQ cycle.

FIG. 17 illustrates an embodiment of a first logic flow.

FIG. 18 illustrates an embodiment of a second logic flow.

FIG. 19A illustrates an embodiment of a first storage medium.

FIG. 19B illustrates an embodiment of a second storage medium.

FIG. 20 illustrates an embodiment of a first device.

FIG. 21 illustrates an embodiment of a second device.

FIG. 22 illustrates an embodiment of a wireless network.

DETAILED DESCRIPTION

Various embodiments may be generally directed to latency reductiontechniques for radio access networks. In some embodiments, a reducedtransmission time interval (rTTI) may be implemented in order to reduceair interface latency in a radio access network. In various embodiments,an rTTI block may be defined, and some operations may be performed inrTTI block-wise fashion in order to reduce the marginal overheadassociated with implementation of the rTTI. In some embodiments in whichan rTTI is implemented, demodulation reference signal (DM-RS)granularity may be improved by use of techniques that enable data andreference signals to be multiplexed within a same orthogonal frequencydivision multiplexing (OFDM) symbol. In various embodiments, a currenttransmission time interval (TTI) may be maintained, and latencyreduction may be achieved via the use of novel techniques for one ormore of code block (CB) segmentation, uplink (UL) resource element (RE)mapping, and hybrid automatic repeat request (HARQ) cycle timing. Otherembodiments are described and claimed.

Various embodiments may comprise one or more elements. An element maycomprise any structure arranged to perform certain operations. Eachelement may be implemented as hardware, software, or any combinationthereof, as desired for a given set of design parameters or performanceconstraints. Although an embodiment may be described with a limitednumber of elements in a certain topology by way of example, theembodiment may include more or less elements in alternate topologies asdesired for a given implementation. It is worthy to note that anyreference to “one embodiment” or “an embodiment” means that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment. The appearances ofthe phrases “in one embodiment,” “in some embodiments,” and “in variousembodiments” in various places in the specification are not necessarilyall referring to the same embodiment.

The techniques disclosed herein may involve transmission of data overone or more wireless connections using one or more wireless mobilebroadband technologies. For example, various embodiments may involvetransmissions over one or more wireless connections according to one ormore 3rd Generation Partnership Project (3GPP), 3GPP Long Term Evolution(LTE), and/or 3GPP LTE-Advanced (LTE-A) technologies and/or standards,including their revisions, progeny and variants. Various embodiments mayadditionally or alternatively involve transmissions according to one ormore Global System for Mobile Communications (GSM)/Enhanced Data Ratesfor GSM Evolution (EDGE), Universal Mobile Telecommunications System(UMTS)/High Speed Packet Access (HSPA), and/or GSM with General PacketRadio Service (GPRS) system (GSM/GPRS) technologies and/or standards,including their revisions, progeny and variants.

Examples of wireless mobile broadband technologies and/or standards mayalso include, without limitation, any of the Institute of Electrical andElectronics Engineers (IEEE) 802.16 wireless broadband standards such asIEEE 802.16m and/or 802.16p, International Mobile TelecommunicationsAdvanced (IMT-ADV), Worldwide Interoperability for Microwave Access(WiMAX) and/or WiMAX II, Code Division Multiple Access (CDMA) 2000(e.g., CDMA200 1×RTT, CDMA2000 EV-DO, CDMA EV-DV, and so forth), HighPerformance Radio Metropolitan Area Network (HIPERMAN), WirelessBroadband (WiBro), High Speed Downlink Packet Access (HSDPA), High SpeedOrthogonal Frequency-Division Multiplexing (OFDM) Packet Access (HSOPA),High-Speed Uplink Packet Access (HSUPA) technologies and/or standards,including their revisions, progeny and variants.

Some embodiments may additionally or alternatively involve wirelesscommunications according to other wireless communications technologiesand/or standards. Examples of other wireless communications technologiesand/or standards that may be used in various embodiments may include,without limitation, other IEEE wireless communication standards such asthe IEEE 802.11, IEEE 802.11a, IEEE 802.11b, IEEE 802.11g, IEEE 802.11n,IEEE 802.11u. IEEE 802.11ac, IEEE 802.11ad, IEEE 802.11af, and/or IEEE802.11ah standards, High-Efficiency Wi-Fi standards developed by theIEEE 802.11 High Efficiency WLAN (HEW) Study Group, Wi-Fi Alliance (WFA)wireless communication standards such as Wi-Fi, Wi-Fi Direct, Wi-FiDirect Services, Wireless Gigabit (WiGig), WiGig Display Extension(WDE), WiGig Bus Extension (WBE), WiGig Serial Extension (WSE) standardsand/or standards developed by the WFA Neighbor Awareness Networking(NAN) Task Group, machine-type communications (MTC) standards such asthose embodied in 3GPP Technical Report (TR) 23.887, 3GPP TechnicalSpecification (TS) 22.368, and/or 3GPP TS 23.682, and/or near-fieldcommunication (NFC) standards such as standards developed by the NFCForum, including any revisions, progeny, and/or variants of any of theabove. The embodiments are not limited to these examples.

In addition to transmission over one or more wireless connections, thetechniques disclosed herein may involve transmission of content over oneor more wired connections through one or more wired communicationsmedia. Examples of wired communications media may include a wire, cable,metal leads, printed circuit board (PCB), backplane, switch fabric,semiconductor material, twisted-pair wire, co-axial cable, fiber optics,and so forth. The embodiments are not limited in this context.

In a radio access network, one factor that may significantly influenceair interface latency is the minimum time scheduling unit. In an LTEevolved UMTS Terrestrial Radio Access Network (E-UTRAN), the minimumtime scheduling unit is the transmission time interval (TTI), whichcomprises a duration of one subframe (1 millisecond, or 14 OFDMsymbols). Reducing the TTI to one slot (0.5 ms, or 7 OFDM symbols), oreven further to one or few OFDM symbols, may enable a significantreduction in latency. However, implementing a reduced TTI (rTTI) maytend to result in increased amounts of various types of overhead, suchas overhead associated with scheduling-related control information, HARQfeedback, and DM-RS reference signals.

In various embodiments, in order to reduce the marginal overheadassociated with implementation of an rTTI, an rTTI block may be definedto enable some types of operations to be performed in an rTTI block-wisefashion that involves less overhead. In some embodiments, scheduling maybe performed on an rTTI block-wise basis, eliminating the need forindividual TTI scheduling information in the control channel. In variousembodiments, respective HARQ feedback corresponding to multiple rTTIcontained in an rTTI block may be transmitted jointly, once the entirerTTI block has been processed, rather than being transmittedindividually on a per-rTTI basis. In some embodiments, rTTI block-wisescheduling may enable the density of reference signals to be reduced, byexploiting the correlation of channel estimates in the time domain, to alevel comparable to the legacy TTI length.

FIG. 1A illustrates an example of a transmission timing diagram 100 thatmay be representative of various embodiments. As reflected intransmission timing diagram 100, in some embodiments, an rTTI maycoexist with the legacy LTE TTI. In this example, use of an LTE TTI andan rTTI are multiplexed in the frequency domain, occupying disjoint setsof physical resource blocks (PRBs) in respective frequency sub-bands.The LTE TTI 102, which comprises a duration of one subframe, is used insub-bands A, B, and C, while the rTTI is used in sub-bands D and E.During a first LTE TTI 102, per-rTTI scheduling is used in sub-bands Dand E. and thus each rTTI in sub-bands D and E within the first LTE TTI102 contains both data and control regions. During a second LTE TTI 102,rTTI block-wise scheduling is used in sub-bands D and E, according towhich a control region in a first rTTI contains all of the schedulinginformation for the entire rTTI block 104, and thus control regions arenot needed in the rest of the rTTIs of the block. In this example, thelength of rTTI block 104 happens to be equal to the length of each LTETTI 102. In various embodiments, setting the rTTI block length to equalthe legacy LTE TTI of one subframe may have significant advantages interms of re-using legacy LTE control and reference signals. However, itis to be appreciated that other rTTI block sizes are both possible andcontemplated, and the embodiments are not limited in this context.

FIG. 1B illustrates an example of an operating environment 140 that maybe representative of some embodiments. In operating environment 140, aneNB 152 and a UE 154 may exchange various types of wirelesscommunications over an LTE air interface 150 in a radio access networkcell 145. In various embodiments, radio access network cell 145 maycomprise a cell of an E-UTRAN. In some embodiments, eNB 152 may transmitcontrol information 156 to UE 154. In various embodiments, eNB 152 maytransmit control information 156 to UE 154 over a physical downlinkcontrol channel (PDCCH) or an enhanced physical downlink controlchannel. In some embodiments, control information 156 may comprisescheduling information that identifies channel resources that have beenscheduled for use in conjunction with wireless communication between eNB152 and UE 154.

In various embodiments, control information 156 may comprise downlinkscheduling information, and may comprise information identifying channelresources that have been scheduled for use by eNB 152 to transmit data160 to UE 154. In some embodiments, eNB 152 may transmit data 160 to UE154 using physical downlink shared channel (PDSCH) resources specifiedby control information 156. In various embodiments, in conjunction withtransmission of data 160 over the PDSCH, eNB 152 may also transmitdemodulation reference signals (DM-RS) 162 over the PDSCH. In someembodiments, UE 154 may transmit HARQ feedback 164 to eNB 152 in orderto inform eNB 152 of whether UE 154 has successfully received data 160.In various embodiments, UE 154 may transmit HARQ feedback 164 to eNB 152over a physical uplink control channel (PUCCH) or physical uplink sharedchannel (PUSCH).

In some embodiments, UE 154 may transmit control information 158 to eNB152. In various embodiments, UE 154 may transmit control information 158over the PUCCH. In some embodiments, control information 158 maycomprise a request for eNB 152 to schedule channel resources for use byUE 154 to transmit data 166 to eNB 152. In various embodiments, inresponse to such a request, eNB 152 may allocate physical uplink sharechannel (PUSCH) resources to UE 154 for use in transmitting data 166 andmay send control information 156 to UE 154 to notify it of thoseallocated resources. It is worthy of note that in some embodiments, ifUE 154 transmits data to eNB 152 over the PUSCH during the same timeinterval as that during which it transmits control information 158, thenUE 154 may transmit control information 158 over the PUSCH as well,rather than the PUCCH. In various embodiments, UE 154 may then transmitdata 166 to eNB 152 using the PUSCH resources specified by that controlinformation 156. In some embodiments, in conjunction with transmissionof data 166 over the PUSCH, UE 154 may also transmit DM-RS signals 168over the PUSCH. In various embodiments, eNB 152 may transmit HARQfeedback 170 to UE 154 in order to inform UE 154 of whether eNB 152 hassuccessfully received data 160. In some embodiments, eNB 152 maytransmit HARQ feedback 170 to UE 104 over a physical HARQ indicatorchannel (PHICH).

In various embodiments, an rTTI may be implemented in radio accessnetwork cell 145 in order to reduce latency associated withcommunications over LTE air interface 150. In some embodiments, in orderto reduce the marginal overhead associated with implementation of therTTI, one or more of the aforementioned operations may be conducted inan rTTI block-wise fashion. In various embodiments, different rTTI blocksizes may be defined to provide additional flexibility and enablefurther overhead reductions. In some embodiments, some operations may beperformed on an rTTI block-wise basis and others may be performed on aper-rTTI basis. For example, in various embodiments, it may be possibleto schedule individual rTTI but, taking into consideration previouslyscheduled rTTI within an rTTI block, permit some DM-RS signals to not betransmitted and the resources to be used to transmit data instead.Similarly, in some embodiments, a rTTI block-wise HARQ feedbackmechanism may be implemented while per-rTTI scheduling is used. Theembodiments are not limited to these examples.

In various embodiments, eNB 152 may conduct resource scheduling on anrTTI block-wise basis. In some embodiments, in conjunction with rTTIblock-wise scheduling operations, eNB 152 may allocate resources of anrTTI block for use in conjunction with wireless communications betweeneNB 152 and UE 154. In various embodiments, eNB 152 may allocate PDSCHresources of the rTTI block for its own use in transmitting data to UE154. In some embodiments, eNB 152 may allocate PUSCH resources of therTTI block for use by UE 154 in transmitting data to eNB 152. In variousembodiments, eNB 152 may send rTTI block-wise scheduling information toUE 154 in order to inform UE 154 of the allocated resources of the rTTIblock. In some embodiments. UE 154 may be configured through upper layersignaling to operate in an rTTI block mode. In various embodiments,operating in the rTTI block mode may enable UE 154 to receive rTTIblock-wise scheduling information via legacy control informationformats, such as legacy formats for communication of such controlinformation over the PDCCH or ePDCCH. In some embodiments, operating inthe rTTI block mode may enable UE 154 to receive DM-RS signals via alegacy DM-RS location defined for the PDSCH.

In various embodiments, eNB 152 may be able schedule an rTTI block suchthat different rTTIs of the block are assigned to different UEs. In someembodiments, eNB 152 may schedule an rTTI block to be shared amongmultiple UEs according to a pattern associated with an rTTI blocksharing format. In an example embodiment, eNB 152 may schedule an rTTIblock to be shared by UE 154 and a second UE according to a patterncomprising alternating, from rTTI to rTTI in the rTTI block, between UE154 and the second UE. In various embodiments, if UE 154 is to share anrTTI block with one or more other UEs, higher layer signaling may beused to inform UE 154 of which of the rTTIs of the block are assigned toUE 154. In some embodiments, this information may be conveyed via apredetermined flag or via an identifier of a defined rTTI block sharingformat. In various embodiments, respective DM-RS resource element (RE)locations may be selected for each rTTI block sharing format in order toimprove/optimize DM-RS granularity. The embodiments are not limited inthis context.

In some embodiments, the higher layer may be able to dimension theresource region for rTTI block mode in the time domain, the frequencydomain, or both. In various embodiments, the higher layer may performtime domain configuration, according to which particular subframes maybe designated as rTTI block mode subframes. In some embodiments, thehigher layer may perform frequency domain configuration, according towhich particular sub-bands may be designated as rTTI block modesub-bands. In various embodiments, these two techniques may be used incombination. The embodiments are not limited in this context.

In some embodiments, while UE 154 operates in rTTI block mode, a HARQprocess may be mapped to each rTTI transport block (TB). In variousembodiments, UE 154 may aggregate HARQ feedback for all of the rTTIswithin an rTTI block and send the aggregated HARQ feedback to eNB 152 ina single block-wise HARQ feedback message. In some embodiments, theblock-wise HARQ feedback message may provide the aggregated HARQfeedback in the form of an N-bit word, with one bit corresponding toeach of N rTTIs in the rTTI block. In various embodiments, eNB 152 mayprovide rTTI block-wise HARQ feedback to UE 154 in analogous fashion. Insome embodiments, the rTTI block length may equal the LTE TTI of 1subframe, and mechanisms defined by LTE for conventional HARQ feedbackmay be used. In various embodiments, since channel decoding is done ineach rTTI, the decoding/encoding budgets may be shorter than thoseassociated with the legacy system using a conventional 1 subframe TTI.Thus, assuming the length of the rTTI block is 1 ms (the same as 1subframe), the aggregated HARQ-ACK feedback corresponding an rTTI blockin subframe n may be sent in subframe n+X (where X<4). As a specificexample, X may be equal to 2, corresponding to a 1 subframe marginconsidering timing advance and decoding/encoding time budget. Theembodiments are not limited to this example.

In some embodiments, UE 154 may use a legacy control signal format, suchas PUCCH format 2 or PUCCH format 3, to provide aggregated HARQ feedbackfor rTTI block-based downlink data transmissions. In variousembodiments, UE 154 may wait for an entire rTTI block to be received andaccumulate HARQ feedback. Then, UE 154 may use the PUCCH or PUSCH inorder to feed back a coded N-bit word containing values 1 for ACK and 0for NACK for each individual rTTI in the rTTI block. In someembodiments, UE 154 may feed back a single collective ACK or NACK of allof the data transmitted during the rTTI block. For example, in variousembodiments. UE 154 may feed back the values ‘111’ in order to indicatea collective ACK, and may feed back the values ‘000’ to indicate acollective NACK. The embodiments are not limited to this example.

In some embodiments, with respect to HARQ feedback for rTTI block-baseduplink transmissions, the PHICH may be modified to carry encodedACK/NACK words, with each uncoded bit representing one rTTI within theblock and taking values 1 for ACK and 0 for NACK. In variousembodiments, for N rTTI/block, N bits may be further encoded to producean r*N bit word, with r being the code rate. In LTE, ACK/NACK is encodedwith a rate 1/3 repetition code, taking values ‘111’ or ‘000’. In someembodiments, the same code may be used in conjunction with rTTIblock-based HARQ feedback. In various other embodiments, a higher ratemay be used in order to reduce PHICH overhead. In some embodiments, theunmodified PHICH may be used to feed back a single collective ACK/NACKvalue for the rTTI block, taking values ‘111’ when all rTTI are receivedcorrectly and ‘000’ otherwise. The embodiments are not limited to thisexample.

FIG. 2 illustrates an embodiment of a reference signal design 200 thatmay be representative of the DM-RS signal design used in conventionalLTE systems. As shown in FIG. 2, according to the conventional DM-RSsignal design, two symbols per subframe are used for DM-RS signals. Inthis example, the symbols used for DM-RS signals are the shaded symbols3 and 10. Subframe 202 comprises slots 204 and 206. The first DM-RSsignal subframe, subframe 3, is comprised in slot 204. The second DM-RSsignal subframe, subframe 10, is comprised in slot 206. If an rTTI of 1slot is implemented, only one DM-RS symbol will be available per slot.

In conjunction with implementing an rTTI, it may be desirable to havemore granularity in the DM-RS signal so that overhead can be managed anda more reliable channel estimation may be achieved. In order to increasegranularity, it may be desirable that data and reference signals arecombined in a given symbol interval. Described herein are techniquesthat may enable data and reference signals to be combined in suchfashion. In various embodiments, data and Jo reference signals may bemultiplexed in the frequency domain. In some embodiments, this maysimplify channel estimation, since reference symbols are notcontaminated by data. In various embodiments, data and reference signalsmay be multiplexed in the time domain. In some embodiments, this mayprovide a higher number of reference samples but may require morecomplex receiver processing. In various embodiments, the symbol durationmay be reduced in order to enable transmission one or more data symbolsand a reference symbol in a same symbol interval. In some embodiments,subcarrier spacing may be effectively increased by the same factor asthat by which the symbol interval is reduced. In various embodiments,for example, the symbol interval may be halved and the subcarrierspacing may be effectively increased from 15 kHz to 30 kHz. In someembodiments, the cyclic prefix (CP) may be divided into two in order tocover two shortened symbols (e.g. 2.5 us for each divided symbol). Invarious embodiments, OFDMA modulation may be used to multiplex data andreference signals in the frequency domain. The embodiments are notlimited in this context.

FIG. 3 illustrates an embodiment of a reference signal design 300 and anembodiment of a reference signal design 350, both of which may berepresentative of DM-RS signal designs that may be implemented in someembodiments in order to improve DM-RS granularity in conjunction withthe use of an rTTI. Reference signal design 300 corresponds to an rTTI302 comprising a duration of one OFDM symbol, while reference signaldesign 350 corresponds to an rTTI 352 comprising a duration of one slot.According to reference signal designs 300 and 350, data and referencesignals are multiplexed in the frequency domain, such that differentsub-carriers are used to transmit data and reference signals in anygiven OFDM symbol during which reference signals are transmitted.

FIG. 4 illustrates an embodiment of a mapping process 400 that may berepresentative of a first approach to facilitating the multiplexing ofdata and reference signals in the frequency domain according to variousembodiments. Denote by N the total number of sub-carriers allocated to agiven UE, by Nd the number of data symbols, and by Nrs the number ofreference symbols, with Nd+Nrs=N. With respect to mapping process 400,Nd may be selected to be equal to N/k, with integer k. According tomapping process 400, a block of Nd data symbols is first repeated ktimes and then multiplied block-wise by a phase vector φ=[1 exp(j2πa/k),. . . exp(j2a(k−1)/k)], where ‘a’ takes an integer value between 0 andN/Nd-1. After this procedure, the usual DFT spreading with DFT size Nyields an interleaved allocation of sub-carriers, where subcarriersa+bk, b=1, 2, . . . Nd contain data symbols. The remainder ofsub-carriers within block N is empty, and can be used to insert areference signal in the frequency domain. In some embodiments, ashortened DM-RS sequence or a different sequence may be used.

A second approach that may be used to facilitate multiplexing data andreference signals in the frequency domain in various embodiments mayinclude using a different DFT size Nd to spread data symbols, and thenmapping symbols in a subset of the N sub-carriers of the block. In someembodiments, this approach may offer more flexibility since any valuefor Nd may be possible. If Nd=N/k, then this approach may be the same asthe approach embodied in mapping process 400, if the frequency mappingis done in an interleaved manner in the frequency domain.

At the receiver, according the either the first approach or the secondapproach, reference symbols may be used in the frequency domain toestimate the channel and may then be removed. In various embodiments,the remaining signal may first be equalized and may then be transformedwith an IDFT of size N (according to the first approach) or Nd(according to the second approach). In some embodiments, data symbolsmay then be retrieved in the time domain. The embodiments are notlimited in this context.

Data and reference signal multiplexing may offer a great deal offlexibility in the allocation of reference signals. In variousembodiments, patterns may be defined that reduce the mean square errorof channel estimation after applying a suitable interpolation method.FIG. 5 illustrates a multiplexing pattern table 500 that comprisesexamples of patterns that may be suitable for use in some embodiments.

In the “Example Patterns” column of multiplexing pattern table 500, ‘A’denotes a symbol consisting entirely of data symbols. ‘B’ denotes asymbol consisting of interleaved reference and data symbols, consistingof a regular pattern, and starting with a pilot symbol. In variousembodiments, such a symbol may be obtained via an approach describedabove. ‘cs(B,a)’ denotes a cyclic shift of B by ‘a’ subcarriers. In someembodiments, such a symbol may be obtained by phase vectormultiplication, as described above. Multiplexing pattern table 500comprises example patterns for rTTI sizes ranging from 1 to 7 symbols.In various embodiments, a suitable value for ‘n’ may be defined based onvarious considerations, which may vary from embodiment to embodiment. Itis to be appreciated that other patterns and/or combinations of ‘A’ andcyclic shifts of B may be defined in some embodiments, and theembodiments are not limited to the examples listed in multiplexingpattern table 500.

FIGS. 6 and 7 illustrate respective reference signal designs 600 and700. Reference signal designs 600 and 700 both reflect the use of anrTTI of 2 symbols with k=2, and illustrate respective examplemultiplexing patterns comprised in multiplexing pattern table 500 ofFIG. 5. Reference signal design 600 corresponds to the multiplexingpattern ‘ABAcs(B,1)’. Reference signal design 700 corresponds to themultiplexing pattern ‘Bcs(B,1)Bcs(B,1)’. The embodiments are not limitedto these examples.

In various embodiments, OFDMA modulation may be used in order tomultiplex data and Jo reference signals in the frequency domain. In someembodiments, patterns of multiplexing pattern table 500 may be readilyused if OFDM rather than SC/FDMA is used for uplink transmission. Invarious embodiments, it may be possible to adopt a symmetric DM-RSpattern for uplink and downlink signals. The embodiments are not limitedin this context.

FIG. 8 illustrates an embodiment of a reference signal design 800 and anembodiment of a reference signal design 850, both of which may berepresentative of DM-RS signal designs that may be implemented in someembodiments in order to improve DM-RS granularity in conjunction withthe use of an rTTI. Reference signal design 800 corresponds to an rTTI802 comprising a duration of one OFDM symbol, while reference signaldesign 850 corresponds to an rTTI 852 comprising a duration of one slot.According to reference signal designs 800 and 850, data and referencesignals are multiplexed in the time domain, such that overlapping dataand reference signals are transmitted over each subcarrier during anygiven OFDM symbol during which reference signals are transmitted.

In various embodiments, in conjunction with multiplexing data andreference signal in the time domain, a data block of size Nd and a timedomain reference signal of size Nrs, with Nd+Nrs=N, may be generated inthe time domain. In some embodiments, the two blocks may then becombined into a size N block and transformed with a size N DFT. Invarious embodiments, this approach may mix data and reference signals inthe frequency domain. In some embodiments, more advanced receivertechniques may be needed in order to separate them. The embodiments arenot limited in this context.

FIG. 9 illustrates an embodiment of a reference signal design 900 and anembodiment of a reference signal design 950, both of which may berepresentative of DM-RS signal designs that may be implemented invarious embodiments in order to improve DM-RS granularity in conjunctionwith the use of an rTTI. Reference signal design 900 corresponds to anrTTI 902 comprising a duration of one OFDM symbol, while referencesignal design 950 corresponds to an rTTI 952 comprising a duration ofone slot. According to reference signal designs 900 and 950, the symbolduration is halved, such that one data symbol and one reference symbolare transmitted within a same OFDM symbol interval over each subcarrierduring any given OFDM symbol during which reference signals aretransmitted.

In some embodiments, it may be possible to provide sufficient referencesymbols for even very short rTTIs by increasing the sub-carrier spacing.In various embodiments, a shorter rTTI may comprise shorter symbols,corresponding to larger subcarrier spacing. In some embodiments, eithermultiplexed data-DM-RS patterns or pure DM-RS symbols can be used withincreased sub-carrier spacing. In various embodiments, the original CPlength may be distributed to shorter symbols. For example, if a shortersymbol is half of a standard symbol and Jo if the CP length for thestandard symbol is 5 us, the length of each shorter symbol CP may be 2.5us. The embodiments are not limited to this example.

In some embodiments, a conventional LTE TTI of 1 subframe may bemaintained, and latency reductions may be achieved via one or morealternate techniques. According to various techniques, received signalsmay be made available for processing earlier at the receiver, so thatprocessing time, and overall latency, may be reduced. According to sometechniques, a code block (CB) segmentation procedure may be modified sothat code block decoding may begin at the receiver prior to receipt ofthe entire subframe. According to various such techniques, the modifiedCB segmentation procedure may use smaller CBs that take less time toprocess. In some embodiments, a modified UL resource element (RE)mapping may be implemented in conjunction with use of the modified CBsegmentation procedure. In various embodiments, conventional LTE TTI andcontrol channel formats may be maintained, and latency may be reducedaccording to techniques that involve moderate changes to the currentstandard. For ease of understanding, embodiments will be explained basedon an FDD structure unless otherwise noted. However, it is to beappreciated that embodiments are not limited to this structure.

According to contemporary LTE procedures, a CB is not permitted to belarger than a maximum CB size Z of 6144 bits. If a codeword (CW) from aMAC layer transport block (TB) is too large enable its bits to fitwithin a single CB, a CB segmentation procedure is performed. Accordingto the CB segmentation procedure, the CW is broken into multiple CBs,and cyclic redundancy checks (CRCs) are appended at the ends of each ofthe multiple CBs. Channel coding and rate matching are then applied on aper-CB basis, after which the data is concatenated and passed to thechannel interleaver. For ease of explanation, a one-to-one mappingbetween TBs and CWs, such that the number of bits in a CW matches thenumber of bits in its TB, is assumed. However, it is to be appreciatedthat the embodiments are not limited in this context.

In some embodiments, a modified CB segmentation procedure may beimplemented according to which each TB is divided into a fixed number Cof CBs, where C is determined by upper layers. In various embodiments,each TB may be divided into a fixed number C of equal-size CBs. In someembodiments, filler bits may be used in order to reach appropriate CBsizes. It is worthy of note that in various embodiments, depending onthe value of C and the TB size, a TB may be segmented into a greaternumber of CBs according to such a modified CB segmentation procedurethan it would according to the conventional CB segmentation procedurethat segments CBs only if they exceed 6144 bits and only into theminimum number of CBs needed to observe the 6144 bit limit. Theembodiments are not limited in this context.

In some embodiments, a modified CB segmentation procedure may beimplemented according to which a smaller value may be defined for themaximum CB size Z. In various embodiments, according to such a modifiedCB segmentation procedure, the upper layers may be able to configure Zto be equal to any of multiple possible values. For example, in someembodiments, a default value for Z may be defined to be 6144 bits, butupper layers may be able to configure Z to equal other values, such as3072 bits or 1536 bits. In various embodiments, the value of Z may bedefined as a function of a parameter N, which may be predetermined orconfigured by upper layers. In some such embodiments, for example, themaximum CB size Z may be given by one of Equations (1), (2), and (3), asfollows:

$\begin{matrix}{Z = \frac{6144}{N}} & {{Equation}\mspace{14mu} (1)} \\{Z = \lceil \frac{6144}{N} \rceil} & {{Equation}\mspace{14mu} (2)} \\{Z = \lfloor \frac{6144}{N} \rfloor} & {{Equation}\mspace{14mu} (3)}\end{matrix}$

The embodiments are not limited to these examples.

FIG. 10 depicts a resource element (RE) mapping scheme 1000 thatillustrates the manner in which rate-matched bits may be mapped to theREs of PUSCH resource blocks (RBs) according to contemporary LTEprocedures. According to RE mapping scheme 1000, rate-matched bits aremapped to REs in a time-first manner, according to which the REs of anRB pair are filled in a row-wise fashion. During each of a series ofmapping passes, rate-matched bits are mapped to the PUSCH REs of arespective subcarrier. For example, as shown in FIG. 10, therate-matched bits associated with a given CB may be mapped to the PUSCHREs of subcarriers 1004-1 to 1004-6 during respective passes 1002-1 to1002-6.

In various embodiments, mapping rate-matched bits to PUSCH REs in atime-first manner such as that illustrated in FIG. 10 may result inrespective bits associated with a same CB being spread out across theentire breadth of the subframe during the very first mapping pass, evenif the CB is relatively small. Since a receiver may need to receive allof the bits associated with the CB before it can begin decoding the CB,the generation of smaller CBs according to one of the aforementionedmodified CB segmentation procedures may not enable the receiver to begindecoding any earlier when time-first PUSCH RE mapping is used. As such,with respect to the PUSCH, it may be desirable to implement a modifiedRE mapping scheme according to which all of the bits associated with agiven CB may potentially be mapped to PUSCH REs comprised within asubset of the OFDM symbols of the subframe. In some embodiments,implementing such a modified RE mapping scheme in conjunction with oneof the modified CB segmentation techniques discussed above may enable areceiver of a CB transmitted over the PUSCH to begin decoding that CBearlier than it would be able to according to contemporary LTEprocedures.

FIG. 11 depicts an example of a modified RE mapping scheme that may beimplemented Jo in various embodiments in order to support earlierdecoding of CBs transmitted over the PUSCH. According to modified REmapping scheme 1100, rate-matched bits are mapped to PUSCH REs in afrequency-first manner, according to which the PUSCH REs of an RB pairare filled in a column-wise fashion. During each of a series of mappingpasses, rate-matched bits are mapped to the PUSCH REs of a respectiveOFDM symbol. For example, the rate-matched bits associated with the sameCB as that discussed above in reference to FIG. 10 may be mapped to theREs of OFDM symbols 0 to 2 and 4 to 6 during respective passes 1102-1 to1102-3 and 1102-4 to 1102-6.

FIG. 12 depicts a second example of a modified RE mapping scheme thatmay be implemented in some embodiments in order to support earlierdecoding of CBs transmitted over the PUSCH. According to modified REmapping scheme 1200, rate-matched bits are mapped to PUSCH REs of an RBpair in a block-wise time-first manner, according to which the PUSCH REsof the first RB are filled first, in a row-wise fashion, and the PUSCHREs of the second RB are filled second, also in a row-wise fashion.During each of a series of mapping passes, rate-matched bits are mapped,within the OFDM symbols of the RB being filled, to the PUSCH REs of arespective subcarrier. For example, the rate-matched bits associatedwith the same CB as that discussed above in reference to FIGS. 10 and 11may be mapped, within OFDM symbols 0 to 6, to the PUSCH REs ofsubcarriers 1204-1 to 1204-12 during respective passes 1202-1 to1202-12.

It is worthy of note that according to each of the mapping schemesdepicted in FIGS. 10-12, the rate-matched bits of the CB are mapped tohalf of the PUSCH REs of the RB pair. However, unlike RE mapping scheme1000, which maps some of the rate-matched bits to respective PUSCH REsof each of OFDM symbols 0 to 13, modified RE mapping schemes 1100 and1200 map the rate-matched bits only to PUSCH REs comprised in OFDMsymbols 0 to 6. In various embodiments, this may enable a receiver tobegin decoding the CB following OFDM symbol 6, rather than needing towait until after OFDM symbol 13. The embodiments are not limited in thiscontext.

In some embodiments, in order to implement frequency-first mapping ofCBs to be transmitted over the PUSCH, the interleaving process for thoseCBs may be skipped. In various embodiments, in order to implementblock-wise time-first mapping of CBs to be transmitted over the PUSCH, amatrix-based channel interleaver mapping may be applied by N-times. Forinstance, in a non-limiting example, assuming N=2 and Z<6144, an inputvalue C_(mux) of the channel interleaver matrix may be given by one ofEquations (4), (5), and (6) as follows:

$\begin{matrix}{C_{mux} = \frac{N_{symb}^{PUSCH}}{N}} & {{Equation}\mspace{14mu} (4)} \\{C_{mux} = \lceil \frac{N_{symb}^{PUSCH}}{N} \rceil} & {{Equation}\mspace{14mu} (5)} \\{C_{mux} = \lfloor \frac{N_{symb}^{PUSCH}}{N} \rfloor} & {{Equation}\mspace{14mu} (6)}\end{matrix}$

Where C_(mux) represents the number of columns of the matrix andN_(symb) ^(PUSCH) represents the number of SC-FDMA symbols carrying thePUSCH in the subframe. In some embodiments, if N=2, then C_(mux) may beequal to C_(slot). In various embodiments, the interleaver matrix may begiven by Equation (7) as follows:

$\begin{matrix}{M = \begin{bmatrix}{\underset{\_}{y}}_{0} & \ldots & {\underset{\_}{y}}_{C_{m} - 1} & {\underset{\_}{y}}_{R^{\prime}{muxC}_{m}} & \ldots & {\underset{\_}{y}}_{{R^{\prime}{muxC}_{m}} + {({C_{m} - 1})}} & \ldots & {\underset{\_}{y}}_{{R^{\prime}{{muxC}_{m}{({C_{b} - 1})}}} + {({C_{b} - 1})}} \\{\underset{\_}{y}}_{C_{m}} & \ddots & {\underset{\_}{y}}_{{2C_{m}} - 1} & \vdots & \; & \vdots & \; & \vdots \\\vdots & \; & \; & \; & \; & \; & \; & \; \\{\underset{\_}{y}}_{{({{R^{\prime}{mux}} - 1})}C_{m}} & \ldots & {\underset{\_}{y}}_{{R^{\prime}{muxC}_{m}} - 1} & {\underset{\_}{y}}_{{R^{\prime}{muxC}_{m}} + {{({{R^{\prime}{mux}} - 1})}C_{m}}} & \ldots & {\underset{\_}{y}}_{{2R^{\prime}{muxC}_{m}} - 1} & \ldots & {\underset{\_}{y}}_{{R^{\prime}{muxC}_{m}C_{b}} - 1}\end{bmatrix}} & (7)\end{matrix}$

Where C_(m) represents C_(mux), and C_(b) represents the number ofblocks. The embodiments are not limited to this example.

FIG. 13 illustrates a HARQ cycle 1300 that may be representative ofconventional LTE procedures. With respect to HARQ cycle 1300 and each ofthe various additional HARQ cycles discussed below, it is assumed thatdecoding time for a CB is proportional to CB transmission time, and thatthe amount of time required at the transmitter to process received HARQfeedback for a CB is the same as the amount of time that was required atthe receiver to process that CB after receiving it from the transmitter.With respect to HARQ cycle 1300 in particular, it is assumed that the CBdecoding time is three times the CB transmission time. It is to beunderstood, however, that these assumptions are adopted merely for easeof explanation, and that the embodiments are not limited in thiscontext.

In HARQ cycle 1300, a transmitter transmits the data associated with aCB to a receiver. In this example, it takes the transmitter one subframe(subframe 1) to transmit the data associated with the CB to thereceiver. The receiver decodes the data during the next three subframes(subframes 2 to 4), and then transmits HARQ feedback (FB) for the dataduring subframe 5. The transmitter decodes the FB during the next threesubframes (subframes 6 to 8). HARQ cycle 1300 thus spans subframes 1 to8, a duration of 8 ms.

FIG. 13 also illustrates a HARQ cycle 1350. HARQ cycle 1350 may berepresentative of some embodiments in which it takes one subframe totransmit the data associated with the same CB as that of HARQ cycle1300, but the CB decoding time is equal to the CB transmission time. InHARQ cycle 1350, as in HARQ cycle 1300, the transmitter transmits thedata associated with the CB to the receiver during subframe 1. Thereceiver decodes the data during subframe 2, and then transmits FB forthe data during subframe 3. The transmitter decodes the FB duringsubframe 4. HARQ cycle 1350 thus spans subframes 1 to 4, a duration of 4ms.

FIG. 14 illustrates a HARQ cycle 1400 that may be representative ofvarious embodiments in which the CB decoding time is three times the CBtransmission time, but the CB transmission time for the same CB as thatof HARQ cycles 1300 and 1350 of FIG. 3 is only one slot instead of onesubframe. In some embodiments, one or more of the modified CBsegmentation techniques and/or modified RE mapping schemes discussedabove may be implemented in order to make it possible to transmit thedata associated with the CB within one slot. In HARQ cycle 1400, thetransmitter transmits the data associated with the CB to the receiverduring the first slot of subframe 1. The receiver decodes the dataduring the next three slots, which comprise the second slot of subframe1 and both slots of subframe 2. The receiver transmits FB for the dataduring the first slot of subframe 3. The transmitter decodes the FBduring the next three slots, which comprise the second slot of subframe3 and both slots of subframe 4. HARQ cycle 1400 thus spans subframes 1to 4, a duration of 4 ms. This constitutes a latency reduction of 4 mswith respect to the 8 ms duration of HARQ cycle 1300 of FIG. 13,according to which the CB transmission time was one subframe instead ofone slot.

FIG. 14 also illustrates a HARQ cycle 1450. HARQ cycle 1450 may berepresentative of various embodiments in which the CB transmission timefor the same CB as that of HARQ cycles 1300, 1350, and 1400 is one slotand the CB decoding time is the same as the CB transmission time. Insome embodiments, one or more of the modified CB segmentation techniquesand/or modified RE mapping schemes discussed above may be implemented inorder to make it possible to transmit the data associated with the CBwithin one slot. In HARQ cycle 1450, as in HARQ cycle 1400, thetransmitter transmits the data associated with the CB to the receiverduring the first slot of subframe 1. The receiver decodes the dataduring the second slot of subframe 1, and then transmits FB for the dataduring the first slot of subframe 2. The transmitter decodes the FBduring the second slot of subframe 2. HARQ cycle 1450 thus spanssubframes 1 to 2, a duration of 2 ms. This constitutes a latencyreduction of 2 ms with respect to the 4 ms duration of HARQ cycle 1350of FIG. 13, according to which the CB decoding time was equal to the CBtransmission time, but the CB transmission time was one subframe insteadof one slot. The embodiments are not limited to these examples.

In various embodiments in which latency reductions are achieved via oneor more of the modified CB segmentation techniques and/or modified REmapping schemes discussed above, a modified HARQ cycle timing scheme maybe implemented in order to account for the reduced transmission anddecoding delays. In some embodiments, a variable duration HARQ cycle maybe implemented, according to which the HARQ cycle duration may beconfigured by upper layer signaling. The embodiments are not limited inthis context.

FIG. 15 illustrates a HARQ cycle 1500 that may be representative ofvarious embodiments in which the CB transmission time is one slot, CBdecoding time is three times the CB transmission time, and respectivefeedback for each CB is transmitted separately. In HARQ cycle 1500, thetransmitter transmits the data (D1) associated with a first CB duringthe first slot of subframe 1, and transmits the data (D2) associatedwith a second CB during the second slot of subframe 1. The receiverdecodes D1 during the second slot of subframe 1 and both slots ofsubframe 2, and sends feedback (FB1) for D1 during the first slot ofsubframe 3. The receiver decodes D2 during both slots of subframe 2 andthe first slot of subframe 3, and then must wait until the first slot ofsubframe 4 to send feedback (FB2) for D2. The transmitter decodes FB1during the second slot of subframe 3 and both slots of subframe 4, anddecodes FB2 during the 20 second slot of subframe 4 and both slots ofsubframe 5. HARQ cycle 1500 thus spans subframes 1 to 5, a duration of 5ms.

FIG. 16 illustrates a HARQ cycle 1600 that may be representative of someembodiments in which the CB transmission time is one slot, CB decodingtime is three times the CB transmission time, and the respectivefeedback for multiple CBs may be aggregated and transmitted jointly. InHARQ cycle 1600, the transmitter transmits the data (D1) associated withthe same first CB as that of HARQ cycle 1500 of FIG. 15 during the firstslot of subframe 1, and transmits the data (D2) associated with the samesecond CB as that of HARQ cycle 1500 during the second slot of subframe1. The receiver decodes D1 during the second slot of subframe 1 and bothslots of subframe 2. However, in contrast to HARQ cycle 1500 of FIG. 15,in HARQ cycle 1600, the receiver refrains from sending feedback for D1during the first slot of subframe 3. The receiver decodes D2 during bothslots of subframe 2 and the first slot of subframe 3. The receiver thetransmits aggregated feedback (AFB), comprising respective feedback forboth D1 and D2, during the first slot of subframe 4. The transmitterdecodes the AFB during the second slot of subframe 4 and both slots ofsubframe 5. HARQ cycle 1600 thus spans subframes 1 to 5, a duration of 5ms, which is the same as that of HARQ cycle 1500 of FIG. 15. Incomparison to HARQ cycle 1500. HARQ cycle 1600 involves less overhead,since only one HARQ feedback message is transmitted rather than the twothat are transmitted in HARQ cycle 1500. On the other hand, according toHARQ cycle 1600, the arrival of feedback for D1 at the transmitter isdelayed by one subframe, as this feedback is contained in the AFBtransmitted during the first slot of subframe 4, rather than arrivingvia a separate transmission during the first slot of subframe 3 as itdoes in HARQ cycle 1500. The embodiments are not limited to theseexamples.

Operations for the above embodiments may be further described withreference to the following figures and accompanying examples. Some ofthe figures may include a logic flow. Although such figures presentedherein may include a particular logic flow, it can be appreciated thatthe logic flow merely provides an example of how the generalfunctionality as described herein can be implemented. Further, the givenlogic flow does not necessarily have to be executed in the orderpresented unless otherwise indicated. In addition, the given logic flowmay be implemented by a hardware element, a software element executed bya processor, or any combination thereof. The embodiments are not limitedin this context.

FIG. 17 illustrates an embodiment of a logic flow 1700, which may berepresentative of the operations executed by one or more embodimentsdescribed herein. For example, logic flow 1700 may be representative ofoperations that may be performed in some embodiments by UE 154 inoperating environment 140 of FIG. 1B. As shown in FIG. 17, controlinformation for an rTTI block comprising a plurality of rTTIs may beaccessed at 1702, where the plurality of rTTIs includes one or morerTTIs assigned to a UE. For example, UE 154 of FIG. 1B may accesscontrol information 156, which may constitute control information for anrTTI block comprising a plurality of rTTIs including one or more rTTIsassigned to UE 154. At 1704, resources of each of the one or more rTTIsassigned to the UE may be identified based on the control information.For example, UE 154 of FIG. 1B may identify resources of the one or morerTTIs based on control information 156. At 1706, wireless communicationwith an eNB may be performed via resources of at least one of the one ormore rTTIs. For example, UE 154 of FIG. 1B may receive data 160 from eNB152 via identified resources of at least one of the one or more rTTIs.In another example, UE 154 may transmit data 166 to eNB 152 viaidentified resources of at least one of the one or more rTTIs. Theembodiments are not limited to these examples.

FIG. 18 illustrates an embodiment of a logic flow 1800, which may berepresentative of the operations executed by one or more embodimentsdescribed herein. For example, logic flow 1800 may be representative ofoperations that may be performed in some embodiments by eNB 152 inoperating environment 140 of FIG. 1B. As shown in FIG. 18, one or morerTTIs may be assigned to a UE at 1802, where the one or more rTTIs arecomprised among a plurality of rTTIs of an rTTI block. For example, eNB152 of FIG. 1B may assign one or more rTTIs of an rTTI block to UE 154.At 1804, resources of each of the one or more rTTIs may be allocated forcommunication with the UE. For example, eNB 152 of FIG. 1B may allocateresources of each of the one or more rTTIs for communication with UE154. At 1806, during a first rTTI of the rTTI block, control informationmay be transmitted that indicates the respective allocated resources ofeach of the one or more rTTIs. For example, during a first rTTI of anrTTI block comprising one or more rTTIs that it has assigned to UE 154,eNB 152 may transmit control information 156, which may indicaterespective allocated resources of each of those one or more rTTIs. Theembodiments are not limited to these examples.

Various embodiments of the invention may be implemented fully orpartially in software and/or firmware. This software and/or firmware maytake the form of instructions contained in or on a non-transitorycomputer-readable storage medium. Those instructions may then be readand executed by one or more processors to enable performance of theoperations described herein. The instructions may be in any suitableform, such as but not limited to source code, compiled code, interpretedcode, executable code, static code, dynamic code, and the like. Such acomputer-readable medium may include any tangible non-transitory mediumfor storing information in a form readable by one or more computers,such as—but not limited to—read only memory (ROM), random access memory(RAM), magnetic disk storage media, optical storage media, semiconductorstorage media, flash memory, etc.

FIG. 19A illustrates an embodiment of a storage medium 1900. Storagemedium 1900 may comprise any non-transitory computer-readable storagemedium or machine-readable storage medium, such as an optical, magneticor semiconductor storage medium. In various embodiments, storage medium1900 may comprise an article of manufacture. In some embodiments,storage medium 1900 may store computer-executable instructions, such ascomputer-executable instructions to implement logic flow 1700 of FIG.17. Examples of a computer-readable storage medium or machine-readablestorage medium may include any tangible media capable of storingelectronic data, including volatile memory or non-volatile memory,removable or non-removable memory, erasable or non-erasable memory,writeable or re-writeable memory, and so forth. Examples ofcomputer-executable instructions may include any suitable type of code,such as source code, compiled code, interpreted code, executable code,static code, dynamic code, object-oriented code, visual code, and thelike. The embodiments are not limited in this context.

FIG. 19B illustrates an embodiment of a storage medium 1950. Storagemedium 1950 may comprise any non-transitory computer-readable storagemedium or machine-readable storage medium, such as an optical, magneticor semiconductor storage medium. In various embodiments, storage medium1950 may comprise an article of manufacture. In some embodiments,storage medium 1950 may store computer-executable instructions, such ascomputer-executable instructions to implement logic flow 1800 of FIG.18. Examples of a computer-readable storage medium or machine-readablestorage medium and of computer-executable instructions may include anyof the respective examples mentioned above in reference to storagemedium 1900 of FIG. 19A. The embodiments are not limited in thiscontext.

As used herein, the term “circuitry” may refer to, be part of, orinclude an Application Specific Integrated Circuit (ASIC), an electroniccircuit, a processor (shared, dedicated, or group), and/or memory(shared, dedicated, or group) that execute one or more software orfirmware programs, a combinational logic circuit, and/or other suitablehardware components that provide the described functionality. In someembodiments, the circuitry may be implemented in, or functionsassociated with the circuitry may be implemented by, one or moresoftware or firmware modules. In some embodiments, circuitry may includelogic, at least partially operable in hardware. Embodiments describedherein may be implemented into a system using any suitably configuredhardware and/or software.

FIG. 20 illustrates an example of a UE device 2000 that may berepresentative of a UE that implements one or more of the disclosedtechniques in various embodiments. For example, UE device 2000 may berepresentative of UE 154 of FIG. 1B according to various embodiments. Insome embodiments, the UE device 2000 may include application circuitry2002, baseband circuitry 2004, Radio Frequency (RF) circuitry 2006,front-end module (FEM) circuitry 2008 and one or more antennas 2010,coupled together at least as shown.

The application circuitry 2002 may include one or more applicationprocessors. For example, the application circuitry 2002 may includecircuitry such as, but not limited to, one or more single-core ormulti-core processors. The processor(s) may include any combination ofgeneral-purpose processors and dedicated processors (e.g., graphicsprocessors, application processors, etc.). The processors may be coupledwith and/or may include memory/storage and may be configured to executeinstructions stored in the memory/storage to enable various applicationsand/or operating systems to run on the system.

The baseband circuitry 2004 may include circuitry such as, but notlimited to, one or more single-core or multi-core processors. Thebaseband circuitry 2004 may include one or more baseband processorsand/or control logic to process baseband signals received from a receivesignal path of the RF circuitry 2006 and to generate baseband signalsfor a transmit signal path of the RF circuitry 2006. Baseband processingcircuitry 2004 may interface with the application circuitry 2002 forgeneration and processing of the baseband signals and for controllingoperations of the RF circuitry 2006. For example, in some embodiments,the baseband circuitry 2004 may include a second generation (2G)baseband processor 2004 a, third generation (3G) baseband processor 2004b, fourth generation (4G) baseband processor 2004 c, and/or otherbaseband processor(s) 2004 d for other existing generations, generationsin development or to be developed in the future (e.g., fifth generation(5G). 6G, etc.). The baseband circuitry 2004 (e.g., one or more ofbaseband processors 2004 a-d) may handle various radio control functionsthat enable communication with one or more radio networks via the RFcircuitry 2006. The radio control functions may include, but are notlimited to, signal modulation/demodulation, encoding/decoding, radiofrequency shifting, etc. In some embodiments, modulation/demodulationcircuitry of the baseband circuitry 2004 may include Fast-Fourier JoTransform (FFT), precoding, and/or constellation mapping/demappingfunctionality. In some embodiments, encoding/decoding circuitry of thebaseband circuitry 2004 may include convolution, tail-bitingconvolution, turbo, Viterbi, and/or Low Density Parity Check (LDPC)encoder/decoder functionality. Embodiments of modulation/demodulationand encoder/decoder functionality are not limited to these examples andmay include other suitable functionality in other embodiments.

In some embodiments, the baseband circuitry 2004 may include elements ofa protocol stack such as, for example, elements of an evolved universalterrestrial radio access network (EUTRAN) protocol including, forexample, physical (PHY), media access control (MAC), radio link control(RLC), packet data convergence protocol (PDCP), and/or radio resourcecontrol (RRC) elements. A central processing unit (CPU) 2004 e of thebaseband circuitry 2004 may be configured to run elements of theprotocol stack for signaling of the PHY, MAC. RLC, PDCP and/or RRClayers. In some embodiments, the baseband circuitry may include one ormore audio digital signal processor(s) (DSP) 2004 f. The audio DSP(s)2004 f may be include elements for compression/decompression and echocancellation and may include other suitable processing elements in otherembodiments. Components of the baseband circuitry may be suitablycombined in a single chip, a single chipset, or disposed on a samecircuit board in some embodiments. In some embodiments, some or all ofthe constituent components of the baseband circuitry 2004 and theapplication circuitry 2002 may be implemented together such as, forexample, on a system on a chip (SOC).

In some embodiments, the baseband circuitry 2004 may provide forcommunication compatible with one or more radio technologies. Forexample, in some embodiments, the baseband circuitry 2004 may supportcommunication with an evolved universal terrestrial radio access network(EUTRAN) and/or other wireless metropolitan area networks (WMAN), awireless local area network (WLAN), a wireless personal area network(WPAN). Embodiments in which the baseband circuitry 2004 is configuredto support radio communications of more than one wireless protocol maybe referred to as multi-mode baseband circuitry.

RF circuitry 2006 may enable communication with wireless networks usingmodulated electromagnetic radiation through a non-solid medium. Invarious embodiments, the RF circuitry 2006 may include switches,filters, amplifiers, etc. to facilitate the communication with thewireless network. RF circuitry 2006 may include a receive signal pathwhich may include circuitry to down-convert RF signals received from theFEM circuitry 2008 and provide baseband signals to the basebandcircuitry 2004. RF circuitry 2006 may also include a transmit signalpath which may include circuitry to up-convert baseband signals Joprovided by the baseband circuitry 2004 and provide RF output signals tothe FEM circuitry 2008 for transmission.

In some embodiments, the RF circuitry 2006 may include a receive signalpath and a transmit signal path. The receive signal path of the RFcircuitry 2006 may include mixer circuitry 2006 a, amplifier circuitry2006 b and filter circuitry 2006 c. The transmit signal path of the RFcircuitry 2006 may include filter circuitry 2006 c and mixer circuitry2006 a. RF circuitry 2006 may also include synthesizer circuitry 2006 dfor synthesizing a frequency for use by the mixer circuitry 2006 a ofthe receive signal path and the transmit signal path. In someembodiments, the mixer circuitry 2006 a of the receive signal path maybe configured to down-convert RF signals received from the FEM circuitry2008 based on the synthesized frequency provided by synthesizercircuitry 2006 d. The amplifier circuitry 2006 b may be configured toamplify the down-converted signals and the filter circuitry 2006 c maybe a low-pass filter (LPF) or band-pass filter (BPF) configured toremove unwanted signals from the down-converted signals to generateoutput baseband signals. Output baseband signals may be provided to thebaseband circuitry 2004 for further processing. In some embodiments, theoutput baseband signals may be zero-frequency baseband signals, althoughthis is not a requirement. In some embodiments, mixer circuitry 2006 aof the receive signal path may comprise passive mixers, although thescope of the embodiments is not limited in this respect.

In some embodiments, the mixer circuitry 2006 a of the transmit signalpath may be configured to up-convert input baseband signals based on thesynthesized frequency provided by the synthesizer circuitry 2006 d togenerate RF output signals for the FEM circuitry 2008. The basebandsignals may be provided by the baseband circuitry 2004 and may befiltered by filter circuitry 2006 c. The filter circuitry 2006 c mayinclude a low-pass filter (LPF), although the scope of the embodimentsis not limited in this respect.

In some embodiments, the mixer circuitry 2006 a of the receive signalpath and the mixer circuitry 2006 a of the transmit signal path mayinclude two or more mixers and may be arranged for quadraturedownconversion and/or upconversion respectively. In some embodiments,the mixer circuitry 2006 a of the receive signal path and the mixercircuitry 2006 a of the transmit signal path may include two or moremixers and may be arranged for image rejection (e.g., Hartley imagerejection). In some embodiments, the mixer circuitry 2006 a of thereceive signal path and the mixer circuitry 2006 a may be arranged fordirect downconversion and/or direct upconversion, respectively. In someembodiments, the mixer circuitry 2006 a of the receive signal path andthe mixer circuitry 2006 a of the transmit signal path may be configuredfor super-heterodyne operation.

In some embodiments, the output baseband signals and the input basebandsignals may be analog baseband signals, although the scope of theembodiments is not limited in this respect. In some alternateembodiments, the output baseband signals and the input baseband signalsmay be digital baseband signals. In these alternate embodiments, the RFcircuitry 2006 may include analog-to-digital converter (ADC) anddigital-to-analog converter (DAC) circuitry and the baseband circuitry2004 may include a digital baseband interface to communicate with the RFcircuitry 2006.

In some dual-mode embodiments, a separate radio IC circuitry may beprovided for processing signals for each spectrum, although the scope ofthe embodiments is not limited in this respect.

In some embodiments, the synthesizer circuitry 2006 d may be afractional-N synthesizer or a fractional N/N+1 synthesizer, although thescope of the embodiments is not limited in this respect as other typesof frequency synthesizers may be suitable. For example, synthesizercircuitry 2006 d may be a delta-sigma synthesizer, a frequencymultiplier, or a synthesizer comprising a phase-locked loop with afrequency divider.

The synthesizer circuitry 2006 d may be configured to synthesize anoutput frequency for use by the mixer circuitry 2006 a of the RFcircuitry 2006 based on a frequency input and a divider control input.In some embodiments, the synthesizer circuitry 2006 d may be afractional N/N+1 synthesizer.

In some embodiments, frequency input may be provided by a voltagecontrolled oscillator (VCO), although that is not a requirement. Dividercontrol input may be provided by either the baseband circuitry 2004 orthe applications processor 2002 depending on the desired outputfrequency. In some embodiments, a divider control input (e.g., N) may bedetermined from a look-up table based on a channel indicated by theapplications processor 2002.

Synthesizer circuitry 2006 d of the RF circuitry 2006 may include adivider, a delay-locked loop (DLL), a multiplexer and a phaseaccumulator. In some embodiments, the divider may be a dual modulusdivider (DMD) and the phase accumulator may be a digital phaseaccumulator (DPA). In some embodiments, the DMD may be configured todivide the input signal by either N or N+1 (e.g., based on a carry out)to provide a fractional division ratio. In some example embodiments, theDLL may include a set of cascaded, tunable, delay elements, a phasedetector, a charge pump and a D-type flip-flop. In these embodiments,the delay elements may be configured to break a VCO period up into Ndequal packets of phase, where Nd is the number of delay elements in thedelay line. In this way, the DLL provides negative feedback to helpensure that the total delay through the delay line is one VCO cycle.

In some embodiments, synthesizer circuitry 2006 d may be configured togenerate a carrier frequency as the output frequency, while in otherembodiments, the output frequency may be a multiple of the carrierfrequency (e.g., twice the carrier frequency, four times the carrierfrequency) and used in conjunction with quadrature generator and dividercircuitry to generate multiple signals at the carrier frequency withmultiple different phases with respect to each other. In someembodiments, the output frequency may be a LO frequency (fLO). In someembodiments, the RF circuitry 2006 may include an IQ/polar converter.

FEM circuitry 2008 may include a receive signal path which may includecircuitry configured to operate on RF signals received from one or moreantennas 2010, amplify the received signals and provide the amplifiedversions of the received signals to the RF circuitry 2006 for furtherprocessing. FEM circuitry 2008 may also include a transmit signal pathwhich may include circuitry configured to amplify signals fortransmission provided by the RF circuitry 2006 for transmission by oneor more of the one or more antennas 2010.

In some embodiments, the FEM circuitry 2008 may include a TX/RX switchto switch between transmit mode and receive mode operation. The FEMcircuitry may include a receive signal path and a transmit signal path.The receive signal path of the FEM circuitry may include a low-noiseamplifier (LNA) to amplify received RF signals and provide the amplifiedreceived RF signals as an output (e.g., to the RF circuitry 2006). Thetransmit signal path of the FEM circuitry 2008 may include a poweramplifier (PA) to amplify input RF signals (e.g., provided by RFcircuitry 2006), and one or more filters to generate RF signals forsubsequent transmission (e.g., by one or more of the one or moreantennas 2010.

In some embodiments, the UE device 2000 may include additional elementssuch as, for example, memory/storage, display, camera, sensor, and/orinput/output (I/O) interface.

FIG. 21 illustrates an embodiment of a communications device 2100 thatmay implement one or more of eNB 152 and UE 154 of FIG. 1B, logic flow1700 of FIG. 17, logic flow 1800 of FIG. 18, storage medium 1900 of FIG.19A, storage medium 1950 of FIG. 19B, and UE 2000 of FIG. 20. In variousembodiments, device 2100 may comprise a logic circuit 2128. The logiccircuit 2128 may include physical circuits to perform operationsdescribed for one or more of eNB 152 and UE 154 of FIG. 1B, logic flow1700 of FIG. 17, logic flow 1800 of FIG. 18, and UE 2000 of FIG. 20 forexample. As shown in FIG. 21, device 2100 may include a radio interface2110, baseband circuitry 2120, and computing platform 2130, although theembodiments are not limited to this configuration.

The device 2100 may implement some or all of the structure and/oroperations for one or more of eNB 152 and UE 154 of FIG. 1B, logic flow1700 of FIG. 17, logic flow 1800 of FIG. 18, storage medium 1900 of FIG.19A, storage medium 1950 of FIG. 19B, UE 2000 of FIG. 20, and logiccircuit 2128 in a single computing entity, such as entirely within asingle device. Alternatively, the device 2100 may distribute portions ofthe structure and/or operations for one or more of eNB 152 and UE 154 ofFIG. 1B, logic flow 1700 of FIG. 17, logic flow 1800 of FIG. 18, storagemedium 1900 of FIG. 19A, storage medium 1950 of FIG. 19B, UE 2000 ofFIG. 20, and logic circuit 2128 across multiple computing entities usinga distributed system architecture, such as a client-server architecture,a 3-tier architecture, an N-tier architecture, a tightly-coupled orclustered architecture, a peer-to-peer architecture, a master-slavearchitecture, a shared database architecture, and other types ofdistributed systems. The embodiments are not limited in this context.

In one embodiment, radio interface 2110 may include a component orcombination of components adapted for transmitting and/or receivingsingle-carrier or multi-carrier modulated signals (e.g., includingcomplementary code keying (CCK), orthogonal frequency divisionmultiplexing (OFDM), and/or single-carrier frequency division multipleaccess (SC-FDMA) symbols) although the embodiments are not limited toany specific over-the-air interface or modulation scheme. Radiointerface 2110 may include, for example, a receiver 2112, a frequencysynthesizer 2114, and/or a transmitter 2116. Radio interface 2110 mayinclude bias controls, a crystal oscillator and/or one or more antennas2118-f In another embodiment, radio interface 2110 may use externalvoltage-controlled oscillators (VCOs), surface acoustic wave filters,intermediate frequency (IF) filters and/or RF filters, as desired. Dueto the variety of potential RF interface designs an expansivedescription thereof is omitted.

Baseband circuitry 2120 may communicate with radio interface 2110 toprocess receive and/or transmit signals and may include, for example, amixer for down-converting received RF signals, an analog-to-digitalconverter 2122 for converting analog signals to digital form, adigital-to-analog converter 2124 for converting digital signals toanalog form, and a mixer for up-converting signals for transmission.Further, baseband circuitry 2120 may include a baseband or physicallayer (PHY) processing circuit 2126 for PHY link layer processing ofrespective receive/transmit signals. Baseband circuitry 2120 mayinclude, for example, a medium access control (MAC) processing circuit2127 for MAC/data link layer processing. Baseband circuitry 2120 mayinclude a memory controller 2132 for communicating with MAC processingcircuit 2127 and/or a computing platform 2130, for example, via one ormore interfaces 2134.

In some embodiments, PHY processing circuit 2126 may include a frameconstruction and/or detection module, in combination with additionalcircuitry such as a buffer memory, to construct and/or deconstructcommunication frames. Alternatively or in addition, MAC processingcircuit 2127 may share processing for certain of these functions orperform these processes independent of PHY processing circuit 2126. Insome embodiments, MAC and PHY processing may be integrated into a singlecircuit.

The computing platform 2130 may provide computing functionality for thedevice 2100. As shown, the computing platform 2130 may include aprocessing component 2140. In addition to, or alternatively of, thebaseband circuitry 2120, the device 2100 may execute processingoperations or logic for one or more of eNB 152 and UE 154 of FIG. 1B,logic flow 1700 of FIG. 17, logic flow 1800 of FIG. 18, storage medium1900 of FIG. 19A, storage medium 1950 of FIG. 19B, UE 2000 of FIG. 20,and logic circuit 2128 using the processing component 2140. Theprocessing component 2140 (and/or PHY 2126 and/or MAC 2127) may comprisevarious hardware elements, software elements, or a combination of both.Examples of hardware elements may include devices, logic devices,components, processors, microprocessors, circuits, processor circuits,circuit elements (e.g., transistors, resistors, capacitors, inductors,and so forth), integrated circuits, application specific integratedcircuits (ASIC), programmable logic devices (PLD), digital signalprocessors (DSP), field programmable gate array (FPGA), memory units,logic gates, registers, semiconductor device, chips, microchips, chipsets, and so forth. Examples of software elements may include softwarecomponents, programs, applications, computer programs, applicationprograms, system programs, software development programs, machineprograms, operating system software, middleware, firmware, softwaremodules, routines, subroutines, functions, methods, procedures, softwareinterfaces, application program interfaces (API), instruction sets,computing code, computer code, code segments, computer code segments,words, values, symbols, or any combination thereof. Determining whetheran embodiment is implemented using hardware elements and/or softwareelements may vary in accordance with any number of factors, such asdesired computational rate, power levels, heat tolerances, processingcycle budget, input data rates, output data rates, memory resources,data bus speeds and other design or performance constraints, as desiredfor a given implementation.

The computing platform 2130 may further include other platformcomponents 2150. Other platform components 2150 include common computingelements, such as one or more processors, multi-core processors,co-processors, memory units, chipsets, controllers, peripherals,interfaces, oscillators, timing devices, video cards, audio cards,multimedia input/output (I/O) components (e.g., digital displays), powersupplies, and so forth. Examples of memory units may include withoutlimitation various types of computer readable and machine readablestorage media in the form of one or more higher speed memory units, suchas read-only memory (ROM), random-access memory (RAM), dynamic RAM(DRAM), Double-Data-Rate DRAM (DDRAM), synchronous DRAM (SDRAM), staticRAM (SRAM), programmable ROM (PROM), erasable programmable ROM (EPROM),electrically erasable programmable ROM (EEPROM), flash memory, polymermemory such as ferroelectric polymer memory, ovonic memory, phase changeor ferroelectric memory, silicon-oxide-nitride-oxide-silicon (SONOS)memory, magnetic or optical cards, an array of devices such as RedundantArray of Independent Disks (RAID) drives, solid state memory devices(e.g., USB memory, solid state drives (SSD) and any other type ofstorage media suitable for storing information.

Device 2100 may be, for example, an ultra-mobile device, a mobiledevice, a fixed device, a machine-to-machine (M2M) device, a personaldigital assistant (PDA), a mobile computing device, a smart phone, atelephone, a digital telephone, a cellular telephone, user equipment,eBook readers, a handset, a one-way pager, a two-way pager, a messagingdevice, a computer, a personal computer (PC), a desktop computer, alaptop computer, a notebook computer, a netbook computer, a handheldcomputer, a tablet computer, a server, a server array or server farm, aweb server, a network server, an Internet server, a work station, amini-computer, a main frame computer, a supercomputer, a networkappliance, a web appliance, a distributed computing system,multiprocessor systems, processor-based systems, consumer electronics,programmable consumer electronics, game devices, display, television,digital television, set top box, wireless access point, base station,node B, subscriber station, mobile subscriber center, radio networkcontroller, router, hub, gateway, bridge, switch, machine, orcombination thereof. Accordingly, functions and/or specificconfigurations of device 2100 described herein, may be included oromitted in various embodiments of device 2100, as suitably desired.

Embodiments of device 2100 may be implemented using single input singleoutput (SISO) architectures. However, certain implementations mayinclude multiple antennas (e.g., antennas 2118-f) for transmissionand/or reception using adaptive antenna techniques for beamforming orspatial division multiple access (SDMA) and/or using MIMO communicationtechniques.

The components and features of device 2100 may be implemented using anycombination of discrete circuitry, application specific integratedcircuits (ASICs), logic gates and/or single chip architectures. Further,the features of device 2100 may be implemented using microcontrollers,programmable logic arrays and/or microprocessors or any combination ofthe foregoing where suitably appropriate. It is noted that hardware,firmware and/or software elements may be collectively or individuallyreferred to herein as “logic” or “circuit.”

It should be appreciated that the exemplary device 2100 shown in theblock diagram of FIG. 21 may represent one functionally descriptiveexample of many potential implementations. Accordingly, division,omission or inclusion of block functions depicted in the accompanyingfigures does not infer that the hardware components, circuits, softwareand/or elements for implementing these functions would be necessarily bedivided, omitted, or included in embodiments.

FIG. 22 illustrates an embodiment of a broadband wireless access system2200. As shown in FIG. 22, broadband wireless access system 2200 may bean internet protocol (IP) type network comprising an internet 2210 typenetwork or the like that is capable of supporting mobile wireless accessand/or fixed wireless access to internet 2210. In one or moreembodiments, broadband wireless access system 2200 may comprise any typeof orthogonal frequency division multiple access (OFDMA)-based orsingle-carrier frequency division multiple access (SC-FDMA)-basedwireless network, such as a system compliant with one or more of the3GPP LTE Specifications and/or IEEE 802.16 Standards, and the scope ofthe claimed subject matter is not limited in these respects.

In the exemplary broadband wireless access system 2200, radio accessnetworks (RANs) 2212 and 2218 are capable of coupling with evolved nodeBs (eNBs) 2214 and 2220, respectively, to provide wireless communicationbetween one or more fixed devices 2216 and internet 2210 and/or betweenor one or more mobile devices 2222 and Internet 2210. One example of afixed device 2216 and a mobile device 2222 is device 2100 of FIG. 21,with the fixed device 2216 comprising a stationary version of device2100 and the mobile device 2222 comprising a mobile version of device2100. RANs 2212 and 2218 may implement profiles that are capable ofdefining the mapping of network functions to one or more physicalentities on broadband wireless access system 2200. eNBs 2214 and 2220may comprise radio equipment to provide RF communication with fixeddevice 2216 and/or mobile device 2222, such as described with referenceto device 2100, and may comprise, for example, the PHY and MAC layerequipment in compliance with a 3GPP LTE Specification or an IEEE 802.16Standard. eNBs 2214 and 2220 may further comprise an IP backplane tocouple to Internet 2210 via RANs 2212 and 2218, respectively, althoughthe scope of the claimed subject matter is not limited in theserespects.

Broadband wireless access system 2200 may further comprise a visitedcore network (CN) 2224 and/or a home CN 2226, each of which may becapable of providing one or more network functions including but notlimited to proxy and/or relay type functions, for exampleauthentication, authorization and accounting (AAA) functions, dynamichost configuration protocol (DHCP) functions, or domain name servicecontrols or the like, domain gateways such as public switched telephonenetwork (PSTN) gateways or voice over internet protocol (VoIP) gateways,and/or internet protocol (IP) type server functions, or the like.However, these are merely example of the types of functions that arecapable of being provided by visited CN 2224 and/or home CN 2226, andthe scope of the claimed subject matter is not limited in theserespects. Visited CN 2224 may be referred to as a visited CN in the casewhere visited CN 2224 is not part of the regular service provider offixed device 2216 or mobile device 2222, for example where fixed device2216 or mobile device 2222 is roaming away from its respective home CN2226, or where broadband wireless access system 2200 is part of theregular service provider of fixed device 2216 or mobile device 2222 butwhere broadband wireless access system 2200 may be in another locationor state that is not the main or home location of fixed device 2216 ormobile device 2222. The embodiments are not limited in this context.

Fixed device 2216 may be located anywhere within range of one or both ofeNBs 2214 and 2220, such as in or near a home or business to providehome or business customer broadband access to Internet 2210 via eNBs2214 and 2220 and RANs 2212 and 2218, respectively, and home CN 2226. Itis worthy of note that although fixed device 2216 is generally disposedin a stationary location, it may be moved to different locations asneeded. Mobile device 2222 may be utilized at one or more locations ifmobile device 2222 is within range of one or both of eNBs 2214 and 2220,for example. In accordance with one or more embodiments, operationsupport system (OSS) 2228 may be part of broadband wireless accesssystem 2200 to provide management functions for broadband wirelessaccess system 2200 and to provide interfaces between functional entitiesof broadband wireless access system 2200. Broadband wireless accesssystem 2200 of FIG. 22 is merely one type of wireless network showing acertain number of the components of broadband wireless access system2200, and the scope of the claimed subject matter is not limited inthese respects.

Various embodiments may be implemented using hardware elements, softwareelements, or a combination of both. Examples of hardware elements mayinclude processors, microprocessors, circuits, circuit elements (e.g.,transistors, resistors, capacitors, inductors, and so forth), integratedcircuits, application specific integrated circuits (ASIC), programmablelogic devices (PLD), digital signal processors (DSP), field programmablegate array (FPGA), logic gates, registers, semiconductor device, chips,microchips, chip sets, and so forth. Examples of software may includesoftware components, programs, applications, computer programs,application programs, system programs, machine programs, operatingsystem software, middleware, firmware, software modules, routines,subroutines, functions, methods, procedures, software interfaces,application program interfaces (API), instruction sets, computing code,computer code, code segments, computer code segments, words, values,symbols, or any combination thereof. Determining whether an embodimentis implemented using hardware elements and/or software elements may varyin accordance with any number of factors, such as desired computationalrate, power levels, heat tolerances, processing cycle budget, input datarates, output data rates, memory resources, data bus speeds and otherdesign or performance constraints.

One or more aspects of at least one embodiment may be implemented byrepresentative instructions stored on a machine-readable medium whichrepresents various logic within the processor, which when read by amachine causes the machine to fabricate logic to perform the techniquesdescribed herein. Such representations, known as “IP cores” may bestored on a tangible, machine readable medium and supplied to variouscustomers or manufacturing facilities to load into the fabricationmachines that actually make the logic or processor. Some embodiments maybe implemented, for example, using a machine-readable medium or articlewhich may store an instruction or a set of instructions that, ifexecuted by a machine, may cause the machine to perform a method and/oroperations in accordance with the embodiments. Such a machine mayinclude, for example, any suitable processing platform, computingplatform, computing device, processing device, computing system,processing system, computer, processor, or the like, and may beimplemented using any suitable combination of hardware and/or software.The machine-readable medium or article may include, for example, anysuitable type of memory unit, memory device, memory article, memorymedium, storage device, storage article, storage medium and/or storageunit, for example, memory, removable or non-removable media, erasable ornon-erasable media writeable or re-writeable media, digital or analogmedia, hard disk, floppy disk, Compact Disk Read Only Memory (CD-ROM),Compact Disk Recordable (CD-R), Compact Disk Rewriteable (CD-RW),optical disk, magnetic media, magneto-optical media, removable memorycards or disks, various types of Digital Versatile Disk (DVD), a tape, acassette, or the like. The instructions may include any suitable type ofcode, such as source code, compiled code, interpreted code, executablecode, static code, dynamic code, encrypted code, and the like,implemented using any suitable high-level, low-level, object-oriented,visual, compiled and/or interpreted programming language.

The following examples pertain to further embodiments:

Example 1 is a wireless communication method, comprising accessing, atuser equipment (UE), control information for a reduced transmission timeinterval (rTTI) block comprising a plurality of rTTIs including one ormore rTTIs assigned to the UE, identifying resources of each of the oneor more rTTIs based on the control information, and wirelesslycommunicating with an evolved node B (eNB) via resources of at least oneof the one or more rTTIs.

Example 2 is the wireless communication method of Example 1, each of theplurality of rTTIs assigned to the UE.

Example 3 is the wireless communication method of Example 1, theplurality of rTTIs including a least one rTTI assigned to a second UE.

Example 4 is the wireless communication method of Example 3, comprisingidentifying an rTTI block sharing format for the rTTI block, andidentifying the one or more rTTIs assigned to the UE based on the rTTIblock sharing format.

Example 5 is the wireless communication method of Example 4, comprisingidentifying the rTTI block sharing format based on information receivedvia upper layer signaling.

Example 6 is the wireless communication method of any of Examples 4 to5, comprising identifying locations of one or more demodulationreference signal (DM-RS) resources of the rTTI block based on the rTTIblock sharing format.

Example 7 is the wireless communication method of any of Examples 1 to4, locations of demodulation reference signal (DM-RS) resources of therTTI block matching DM-RS resource locations defined for wirelesscommunications performed according to a 1 subframe TTI.

Example 8 is the wireless communication method of any of Examples 1 to7, comprising identifying, from among multiple defined rTTI block sizes,an rTTI block size associated with the rTTI block, and identifying theplurality of rTTIs based on the rTTI block size.

Example 9 is the wireless communication method of any of Examples 1 to8, the rTTI block comprising a duration of 1 ms.

Example 10 is the wireless communication method of any of Examples 1 to9, each of the plurality of rTTIs comprising a duration of 500 μs.

Example 11 is the wireless communication method of any of Examples 1 to9, each of the plurality of rTTIs comprising a duration of oneorthogonal frequency division multiplexing (OFDM) symbol.

Example 12 is the wireless communication method of any of Examples 1 to11, the control information comprised in signals received via resourcesof a first rTTI of the rTTI block.

Example 13 is the wireless communication method of any of Examples 1 to12, comprising operating in an rTTI block mode in response to a blockmode parameter value comprised in a received configuration message, andaccessing the control information while operating in the rTTI blockmode.

Example 14 is the wireless communication method of any of Examples 1 to13, the control information comprising rTTI block-wise schedulinginformation.

Example 15 is the wireless communication method of Example 14, the rTTIblock-wise scheduling information comprising a format matching aphysical DL control channel (PDCCH) DL control information (DCI) format.

Example 16 is the wireless communication method of any of Examples 14 to15, the rTTI block-wise scheduling information comprising downlink (DL)scheduling information.

Example 17 is the wireless communication method of Example 16,comprising receiving data from the eNB over a physical DL shared channel(PDSCH) via resources of the one or more rTTIs assigned to the UE.

Example 18 is the wireless communication method of any of Examples 16 to17, comprising identifying each of multiple rTTIs of the rTTI block thatare assigned to the UE, and receiving data from the eNB via respectiveresources of each of the multiple rTTIs assigned to the UE.

Example 19 is the wireless communication method of Example 18,comprising sending a block-wise hybrid automatic repeat request (HARQ)feedback message to provide HARQ feedback for the data received duringthe multiple rTTIs.

Example 20 is the wireless communication method of Example 19, theblock-wise HARQ feedback message to contain individual HARQ feedback forthe respective data received during each of the multiple rTTIs.

Example 21 is the wireless communication method of Example 19, theblock-wise HARQ feedback message to contain a single collectiveacknowledgment (ACK) or negative acknowledgment (NACK) of all of thedata received during the multiple rTTIs.

Example 22 is the wireless communication method of Example 18,comprising sending a separate HARQ feedback message to provide HARQfeedback for the respective data received during each of the multiplerTTIs.

Example 23 is the wireless communication method of Example 14, the rTTIblock-wise scheduling information comprising uplink (UL) schedulinginformation.

Example 24 is the wireless communication method of Example 23,comprising transmitting data to the eNB over a physical UL sharedchannel (PUSCH) via resources of at least one of the one or more rTTIsassigned to the UE.

Example 25 is the wireless communication method of any of Examples 23 to24, comprising identifying multiple rTTIs of the rTTI block that areassigned to the UE, and transmitting data to the eNB via respectiveresources of each of the multiple rTTIs.

Example 26 is the wireless communication method of Example 25,comprising receiving a block-wise hybrid automatic repeat request (HARQ)feedback message comprising HARQ feedback for the data sent during themultiple rTTIs.

Example 27 is the wireless communication method of Example 26, theblock-wise HARQ feedback message to contain individual HARQ feedback forthe respective data transmitted during each of the multiple rTTIs.

Example 28 is the wireless communication method of Example 26, theblock-wise HARQ feedback to contain a single collective acknowledgment(ACK) or negative acknowledgment (NACK) of all of the data transmittedduring the multiple rTTIs.

Example 29 is the wireless communication method of Example 25,comprising receiving, for each of the multiple rTTIs, a separaterespective HARQ feedback message comprising HARQ feedback for datatransmitted during that rTTI.

Example 30 is an apparatus, comprising at least one memory, and logic,at least a portion of which is implemented in circuitry coupled to theat least one memory, the logic to perform a wireless communicationmethod according to any of Examples 1 to 29.

Example 31 is a system, comprising the apparatus of Example 30, and atleast one radio frequency (RF) transceiver.

Example 32 is the system of Example 31, comprising at least one RFantenna.

Example 33 is the system of any of Examples 31 to 32, comprising atouchscreen display.

Example 34 is at least one computer-readable storage medium comprising aset of wireless communication instructions that, in response to beingexecuted on a computing device, cause the computing device to perform awireless communication method according to any of Examples 1 to 29.

Example 35 is an apparatus, comprising means for performing a wirelesscommunication method according to any of Examples 1 to 29.

Example 36 is a system, comprising the apparatus of Example 35, and atleast one radio frequency (RF) transceiver.

Example 37 is the system of Example 36, comprising at least one RFantenna.

Example 38 is the system of any of Examples 36 to 37, comprising atouchscreen display.

Example 39 is a wireless communication method, comprising assigning, byprocessing circuitry at an evolved node B (eNB), one or more reducedtransmit time intervals (rTTIs) to a user equipment (UE), the one ormore rTTIs comprised among a plurality of rTTIs of an rTTI block,allocating resources of each of the one or more rTTIs for communicationwith the UE, and transmitting control information during a first rTTI ofthe rTTI block, the control information indicating the respectiveallocated resources of each of the one or more rTTIs.

Example 40 is the wireless communication method of Example 39,comprising designating, among a plurality of frequency sub-bands, one ormore rTTI block mode sub-bands, the rTTI block comprising an rTTI blockof one of the one or more rTTI block mode sub-bands.

Example 41 is the wireless communication method of any of Examples 39 to40, comprising designating, among a plurality of subframes, one or morerTTI block mode subframes, the rTTI block comprising an rTTI block ofone of the one or more rTTI block mode subframes.

Example 42 is the wireless communication method of any of Examples 39 to41, comprising sending a configuration message to instruct the UE tooperate in an rTTI block mode.

Example 43 is the wireless communication method of any of Examples 39 to42, comprising assigning each of the plurality of rTTIs to the UE.

Example 44 is the wireless communication method of any of Examples 39 to42, comprising assigning one or more other rTTIs of the rTTI block to asecond UE.

Example 45 is the wireless communication method of Example 44,comprising assigning rTTIs of the rTTI block to the UE and the second UEaccording to a pattern associated with an rTTI block sharing format.

Example 46 is the wireless communication method of Example 45,comprising selecting the rTTI block sharing format from among multiplepredefined rTTI block sharing formats.

Example 47 is the wireless communication method of any of Examples 45 to46, the pattern comprising alternating, from rTTI to rTTI, between theUE and the second UE.

Example 48 is the wireless communication method of any of Examples 39 to47, comprising using upper layer signaling to notify the UE of theidentities of the one or more rTTIs assigned to the UE.

Example 49 is the wireless communication method of any of Examples 39 to48, comprising selecting a size for the rTTI block from among multiplepermitted rTTI block sizes.

Example 50 is the wireless communication method of any of Examples 39 to49, the rTTI block comprising a duration of 1 ms.

Example 51 is the wireless communication method of any of Examples 39 to50, each of the plurality of rTTIs comprising a duration of 500 μs.

Example 52 is the wireless communication method of any of Examples 39 to50, each of the plurality of rTTIs comprising a duration of oneorthogonal frequency division multiplexing (OFDM) symbol.

Example 53 is the wireless communication method of any of Examples 39 to52, the respective allocated resources of each of the one or more rTTIscomprising resources of a physical downlink shared channel (PDSCH).

Example 54 is the wireless communication method of Example 53,comprising allocating respective PDSCH resources of multiple rTTIs ofthe rTTI block for communication with the UE, and transmitting data tothe UE via the allocated PDSCH resources of the multiple rTTIs.

Example 55 is the wireless communication method of Example 54,comprising receiving a block-wise hybrid automatic repeat request (HARQ)feedback message comprising HARQ feedback for the data transmitted tothe UE via the allocated PDSCH resources of the multiple rTTIs.

Example 56 is the wireless communication method of Example 55, theblock-wise HARQ feedback message to contain, for each of the multiplerTTIs, respective individual HARQ feedback of data transmitted to the UEvia the allocated PDSCH resources of that rTTI.

Example 57 is the wireless communication method of Example 55, theblock-wise HARQ feedback message to contain a single collectiveacknowledgment (ACK) or negative acknowledgment (NACK) of all of thedata transmitted to the UE via the allocated PDSCH resources of themultiple rTTIs.

Example 58 is the wireless communication method of Example 54,comprising receiving, for each of the multiple rTTIs, a separaterespective HARQ feedback message comprising HARQ feedback for datatransmitted to the UE via the allocated PDSCH resources of that rTTI.

Example 59 is the wireless communication method of any of Examples 39 to52, the respective allocated resources of each of the one or more rTTIscomprising resources of a physical uplink shared channel (PUSCH).

Example 60 is the wireless communication method of Example 59,comprising allocating respective PUSCH resources of multiple rTTIs ofthe rTTI block for communication with the UE, and receiving data fromthe UE via the allocated PUSCH resources of the multiple rTTIs.

Example 61 is the wireless communication method of Example 60,comprising transmitting a block-wise hybrid automatic repeat request(HARQ) feedback message comprising HARQ feedback for the data receivedfrom the UE via the allocated PUSCH resources of the multiple rTTIs.

Example 62 is the wireless communication method of Example 61, theblock-wise HARQ feedback message to contain, for each of the multiplerTTIs, respective individual HARQ feedback of data received from the UEvia the allocated PUSCH resources of that rTTI.

Example 63 is the wireless communication method of Example 61, theblock-wise HARQ feedback message to contain a single collectiveacknowledgment (ACK) or negative acknowledgment (NACK) of all of thedata received from the UE via the allocated PUSCH resources of themultiple rTTIs.

Example 64 is the wireless communication method of Example 60,comprising transmitting, for each of the multiple rTTIs, a separaterespective HARQ feedback message comprising HARQ feedback for datareceived from the UE via the allocated PUSCH resources of that rTTI.

Example 65 is an apparatus, comprising at least one memory, and logic,at least a portion of which is implemented in circuitry coupled to theat least one memory, the logic to perform a wireless communicationmethod according to any of Examples 39 to 64.

Example 66 is a system, comprising the apparatus of Example 65, and atleast one radio frequency (RF) transceiver.

Example 67 is the system of Example 66, comprising at least one RFantenna.

Example 68 is at least one computer-readable storage medium comprising aset of wireless communication instructions that, in response to beingexecuted on a computing device, cause the computing device to perform awireless communication method according to any of Examples 39 to 64.

Example 69 is an apparatus, comprising means for performing a wirelesscommunication method according to any of Examples 39 to 64.

Example 70 is a system, comprising the apparatus of Example 69, and atleast one radio frequency (RF) transceiver.

Example 71 is the system of Example 70, comprising at least one RFantenna.

Numerous specific details have been set forth herein to provide athorough understanding of the embodiments. It will be understood bythose skilled in the art, however, that the embodiments may be practicedwithout these specific details. In other instances, well-knownoperations, components, and circuits have not been described in detailso as not to obscure the embodiments. It can be appreciated that thespecific structural and functional details disclosed herein may berepresentative and do not necessarily limit the scope of theembodiments.

Some embodiments may be described using the expression “coupled” and“connected” along with their derivatives. These terms are not intendedas synonyms for each other. For example, some embodiments may bedescribed using the terms “connected” and/or “coupled” to indicate thattwo or more elements are in direct physical or electrical contact witheach other. The term “coupled,” however, may also mean that two or moreelements are not in direct contact with each other, but yet stillco-operate or interact with each other.

Unless specifically stated otherwise, it may be appreciated that termssuch as “processing,” “computing.” “calculating,” “determining,” or thelike, refer to the action and/or processes of a computer or computingsystem, or similar electronic computing device, that manipulates and/ortransforms data represented as physical quantities (e.g., electronic)within the computing system's registers and/or memories into other datasimilarly represented as physical quantities within the computingsystem's memories, registers or other such information storage,transmission or display devices. The embodiments are not limited in thiscontext.

It should be noted that the methods described herein do not have to beexecuted in the order described, or in any particular order. Moreover,various activities described with respect to the methods identifiedherein can be executed in serial or parallel fashion.

Although specific embodiments have been illustrated and describedherein, it should be appreciated that any arrangement calculated toachieve the same purpose may be substituted for the specific embodimentsshown. This disclosure is intended to cover any and all adaptations orvariations of various embodiments. It is to be understood that the abovedescription has been made in an illustrative fashion, and not arestrictive one. Combinations of the above embodiments, and otherembodiments not specifically described herein will be apparent to thoseof skill in the art upon reviewing the above description. Thus, thescope of various embodiments includes any other applications in whichthe above compositions, structures, and methods are used.

It is emphasized that the Abstract of the Disclosure is provided tocomply with 37 C.F.R. § 1.72(b), requiring an abstract that will allowthe reader to quickly ascertain the nature of the technical disclosure.It is submitted with the understanding that it will not be used tointerpret or limit the scope or meaning of the claims. In addition, inthe foregoing Detailed Description, it can be seen that various featuresare grouped together in a single embodiment for the purpose ofstreamlining the disclosure. This method of disclosure is not to beinterpreted as reflecting an intention that the claimed embodimentsrequire more features than are expressly recited in each claim. Rather,as the following claims reflect, inventive subject matter lies in lessthan all features of a single disclosed embodiment. Thus the followingclaims are hereby incorporated into the Detailed Description, with eachclaim standing on its own as a separate preferred embodiment. In theappended claims, the terms “including” and “in which” are used as theplain-English equivalents of the respective terms “comprising” and“wherein.” respectively. Moreover, the terms “first,” “second,” and“third,” etc. are used merely as labels, and are not intended to imposenumerical requirements on their objects.

Although the subject matter has been described in language specific tostructural features and/or methodological acts, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described above.Rather, the specific features and acts described above are disclosed asexample forms of implementing the claims.

1. An apparatus, comprising: at least one memory; and logic, at least aportion of which is implemented in circuitry coupled to the at least onememory, the logic to: access, at user equipment (UE), controlinformation for a reduced transmission time interval (rTTI) blockcomprising a plurality of rTTIs including one or more rTTIs assigned tothe UE; identify resources of each of the one or more rTTIs based on thecontrol information; and wirelessly communicate with an evolved node B(eNB) via resources of at least one of the one or more rTTIs.
 2. Theapparatus of claim 1, the logic to: identify an rTTI block sharingformat for the rTTI block; and identify the one or more rTTIs assignedto the UE based on the rTTI block sharing format.
 3. The apparatus ofclaim 1, the logic to: identify, from among multiple defined rTTI blocksizes, an rTTI block size associated with the rTTI block; andidentifying the plurality of rTTIs based on the rTTI block size.
 4. Theapparatus of claim 1, the rTTI block to comprise a duration of onesubframe.
 5. The apparatus of claim 1, the control information tocomprise rTTI block-wise downlink scheduling information identifyingallocated physical downlink shared channel (PDSCH) resources of multiplerTTIs of the rTTI block, the rTTI block-wise downlink schedulinginformation to comprise a format matching a physical downlink controlchannel (PDCCH) downlink control information (DCI) format.
 6. Theapparatus of claim 5, the logic to: process data received from the eNBvia the PDSCH resources of the multiple rTTIs of the rTTI block; andgenerate an rTTI block-wise hybrid automatic repeat request (HARQ)feedback message for transmission over a physical uplink control channel(PUCCH) to provide HARQ feedback for the data.
 7. The apparatus of claim6, the rTTI block-wise HARQ feedback message to contain: for each of themultiple rTTIs, respective individual HARQ feedback for data receivedvia the allocated PDSCH resources of that rTTI; or a single collectiveacknowledgment (ACK) or negative acknowledgment (NACK) of all of thedata received via the allocated PDSCH resources of the multiple rTTIs.8. The apparatus of claim 1, the control information to be comprised insignals received via resources of a first rTTI of the rTTI block.
 9. Asystem, comprising: the apparatus of claim 1; at least one radiofrequency (RF) transceiver; and at least one RF antenna.
 10. Anapparatus, comprising: at least one memory; and logic, at least aportion of which is implemented in circuitry coupled to the at least onememory, the logic to: assign one or more reduced transmit time intervals(rTTIs) to user equipment (UE), the one or more rTTIs to be comprisedamong a plurality of rTTIs of an rTTI block; allocate resources of eachof the one or more rTTIs for communication with the UE; and generatecontrol information for transmission during a first rTTI of the rTTIblock, the control information to indicate the allocated resources ofeach of the one or more rTTIs.
 11. The apparatus of claim 10, the logicto assign each of the plurality of rTTIs to the UE.
 12. The apparatus ofclaim 10, the logic to: assign the one or more rTTIs to the UE accordingto a pattern associated with an rTTI block sharing format; and assignone or more other rTTIs comprised among the plurality of rTTIs to asecond UE according to the pattern associated with the rTTI blocksharing format.
 13. The apparatus of claim 10, the rTTI block tocomprise a size selected from among multiple permissible rTTI blocksizes.
 14. The apparatus of claim 10, the rTTI block to comprise aduration of one subframe, each of the plurality of rTTIs to comprise aduration of one slot.
 15. The apparatus of claim 10, the allocatedresources to comprise resources of a physical downlink shared channel(PDSCH).
 16. The apparatus of claim 10, the allocated resources tocomprise resources of a physical uplink shared channel (PUSCH).
 17. Theapparatus of claim 10, the logic to: generate rTTI block-wise hybridautomatic repeat request (HARQ) feedback for data received from the UEvia the allocated resources; or process received rTTI block-wise HARQfeedback for data transmitted to the UE via the allocated resources. 18.At least one computer-readable storage medium comprising a set ofinstructions that, in response to being executed at user equipment (UE),cause the UE to: identify control information for a reduced transmissiontime interval (rTTI) block comprising a plurality of rTTIs including oneor more rTTIs assigned to a user equipment (UE), the control informationto be comprised in signals received via resources of a first rTTI of therTTI block; identify resources of each of the one or more rTTIs based onthe control information; and wirelessly communicate with an evolved nodeB (eNB) via resources of at least one of the one or more rTTIs.
 19. Theat least one computer-readable storage medium of claim 18, the controlinformation to comprise rTTI block-wise uplink scheduling information.20. The at least one computer-readable storage medium of claim 19,comprising instructions that, in response to being executed at the UE,cause the UE to transmit data to the eNB over a physical uplink sharedchannel (PUSCH) via resources of multiple rTTIs assigned to the UE. 21.The at least one computer-readable storage medium of claim 20,comprising instructions that, in response to being executed at the UE,cause the UE to receive rTTI block-wise HARQ feedback for the data overa physical HARQ indicator channel (PHICH).
 22. The at least onecomputer-readable storage medium of claim 21, the rTTI block-wise HARQfeedback to comprise: for each of the multiple rTTIs, respectiveindividual HARQ feedback for data transmitted over the PUSCH during thatrTTI; or a single collective acknowledgment (ACK) or negativeacknowledgment (NACK) of all of the data transmitted over the PUSCHduring the multiple rTTIs.
 23. The at least one computer-readablestorage medium of claim 18, the control information to comprise rTTIblock-wise downlink scheduling information identifying allocatedphysical downlink shared channel (PDSCH) resources of each of the one ormore rTTIs assigned to the UE.
 24. The at least one computer-readablestorage medium of claim 18, the rTTI block to comprise a duration of 1ms.
 25. The at least one computer-readable storage medium of claim 18,each of the plurality of rTTIs to comprise a duration of 500 μs.